a: a salt or ester of a phosphoric acid b: the trivalent anion PO43− derived from phosphoric acid H3PO4
: an organic compound of phosphoric acid in which the acid group is bound to nitrogen or a carboxyl group in a way that permits useful energy to be released (as in metabolism)
Any of numerous chemical compounds related to phosphoric acid (HPO). Phosphate salts are inorganic compounds containing the phosphate ion (PO3), the hydrogen phosphate ion (HPO2), or the dihydrogen phosphate ion (HPO), along with any cation. Phosphate esters are organic compounds in which the hydrogens of phosphoric acid are replaced by organic groups (e.g., methyl, ethyl, phenyl), with one of their carbon atoms bonding to an oxygen atom in the phosphate group. Nucleic acids and ATP both contain phosphate; bones and teeth contain calcium phosphate. Phosphate rock (mainly calcium phosphate) is one of the four most important basic chemical commodities. Phosphates were formerly used in detergents, which washed into rivers and lakes, causing water blooms of algae and bacteria (seeeutrophication); such use is now generally outlawed or regulated. Phosphates are still used in fertilizers, baking powder, and toothpaste.